/* Insert d_key'th (delimiting) key from buffer cfr to head of dest.
* Copy n node pointers and n - 1 items from buffer src to buffer dest.
* Replace d_key'th key in buffer cfr.
* Delete n items and node pointers from buffer src.
*/
static void internal_shift_right(int mode, /* INTERNAL_FROM_S_TO_R | INTERNAL_FROM_L_TO_S */
struct tree_balance *tb,
int h, int pointer_amount)
{
struct buffer_info dest_bi, src_bi;
struct buffer_head *cf;
int d_key_position;
int nr;
internal_define_dest_src_infos(mode, tb, h, &dest_bi, &src_bi,
&d_key_position, &cf);
nr = B_NR_ITEMS(src_bi.bi_bh);
if (pointer_amount > 0) {
/* insert delimiting key from common father of dest and src to dest node into position 0 */
internal_insert_key(&dest_bi, 0, cf, d_key_position);
if (nr == pointer_amount - 1) {
RFALSE(src_bi.bi_bh != PATH_H_PBUFFER(tb->tb_path, h) /*tb->S[h] */ ||
dest_bi.bi_bh != tb->R[h],
"src (%p) must be == tb->S[h](%p) when it disappears",
src_bi.bi_bh, PATH_H_PBUFFER(tb->tb_path, h));
/* when S[h] disappers replace left delemiting key as well */
if (tb->CFL[h])
replace_key(tb, cf, d_key_position, tb->CFL[h],
tb->lkey[h]);
} else
replace_key(tb, cf, d_key_position, src_bi.bi_bh,
nr - pointer_amount);
}
/* last parameter is del_parameter */
internal_move_pointers_items(&dest_bi, &src_bi, LAST_TO_FIRST,
pointer_amount, 0);
}
/* this can be invoked both to shift from S to L and from R to S */
static void internal_shift_left(int mode, /* INTERNAL_FROM_S_TO_L | INTERNAL_FROM_R_TO_S */
struct tree_balance *tb,
int h, int pointer_amount)
{
struct buffer_info dest_bi, src_bi;
struct buffer_head *cf;
int d_key_position;
internal_define_dest_src_infos(mode, tb, h, &dest_bi, &src_bi,
&d_key_position, &cf);
/*printk("pointer_amount = %d\n",pointer_amount); */
if (pointer_amount) {
/* insert delimiting key from common father of dest and src to node dest into position B_NR_ITEM(dest) */
internal_insert_key(&dest_bi, B_NR_ITEMS(dest_bi.bi_bh), cf,
d_key_position);
if (B_NR_ITEMS(src_bi.bi_bh) == pointer_amount - 1) {
if (src_bi.bi_position /*src->b_item_order */ == 0)
replace_key(tb, cf, d_key_position,
src_bi.
bi_parent /*src->b_parent */ , 0);
} else
replace_key(tb, cf, d_key_position, src_bi.bi_bh,
pointer_amount - 1);
}
/* last parameter is del_parameter */
internal_move_pointers_items(&dest_bi, &src_bi, FIRST_TO_LAST,
pointer_amount, 0);
}
static int reduce_file_callback(FS *fs, BLOCK *block, KEY *key, EFFECT *effect, void *data)
{
struct reduce_file_baton *baton = (struct reduce_file_baton *) data;
char extent_prefix[MAX_INTERNAL_NAME+1];
unsigned long int start, stop;
unsigned long int first_to_go;
unsigned long int i;
sprintf(extent_prefix, "%ld/X", baton->label);
if (key->type == K_INVALID || strncmp(key->name, extent_prefix, strlen(extent_prefix)) != 0)
return 0;
sscanf(key->name + strlen(extent_prefix), "%ld-%ld", &start, &stop);
if (stop < baton->new_num_blocks)
{
baton->num_blocks = stop+1;
return 0;
}
first_to_go = MAX2(start, baton->new_num_blocks);
for (i = first_to_go; i <= stop; i++)
deallocate_block(fs, B_DATA, key->pointer + (i - start));
if (first_to_go <= start)
delete_key(fs, block, key->name, effect);
else
{
sprintf(extent_prefix, "%ld/X%08ld-%08ld", baton->label, start, first_to_go - 1);
replace_key(fs, block, key->name, extent_prefix, K_ATTRIBUTE, key->pointer, effect);
}
baton->num_blocks = first_to_go;
return 1;
}
static int get_file_data_block_callback(FS *fs, BLOCK *block, KEY *key, EFFECT *effect, void *data)
{
struct get_file_data_block_baton *baton = (struct get_file_data_block_baton *) data;
char extent_prefix[MAX_INTERNAL_NAME+1];
unsigned long int start = -1, stop = -1;
BLOCK *b;
sprintf(extent_prefix, "%ld/X", baton->fh->label);
if (key->type != K_INVALID && strncmp(key->name, extent_prefix, strlen(extent_prefix)) == 0)
{
sscanf(key->name + strlen(extent_prefix), "%ld-%ld", &start, &stop);
if (start <= baton->block_num && baton->block_num <= stop)
{
baton->location = key->pointer + (baton->block_num - start);
return 1;
}
}
b = allocate_block(fs, B_DATA, baton->predecessor);
if (key->type != K_INVALID && strncmp(key->name, extent_prefix, strlen(extent_prefix)) == 0
&& stop == baton->block_num - 1 && key->pointer + (stop - start) == b->location - 1)
{
sprintf(extent_prefix, "%ld/X%08ld-%08ld", baton->fh->label, start, baton->block_num);
replace_key(fs, block, key->name, extent_prefix, K_ATTRIBUTE, key->pointer, effect);
}
else
{
sprintf(extent_prefix, "%ld/X%08ld-%08ld", baton->fh->label, baton->block_num, baton->block_num);
insert_key(fs, block, extent_prefix, K_ATTRIBUTE, b->location, effect);
}
baton->location = b->location;
return 1;
}
